Goitrogenic Effect of Prolonged Treatment with LATS on Mice Immunologically Tolerant to Human Immunoglobulin G 1

Summary

In order to determine whether LATS has a true tropic or goitrogenic effect on mouse thyroid glands, mice were made hyporesponsive to human IgG so that they could receive prolonged treatment with low doses of human LATS-IgG. Groups of mice were treated with TSH, two different doses of LATS, normal human IgG, and saline. The LATS- and TSH-treated mice were found to have lost weight when compared to controls, to have enlarged thyroid glands which had increased rates of RNA and protein synthesis, and to have elevated rates of ¹³¹I uptake. The LATS- and TSH-treated glands showed histologic evidence of hyperactivity, although the LATS glands, in contrast to those treated with TSH, did not show marked colloid resorption. These results derived from prolonged therapy with LATS-IgG in tolerant mice, confirm the thyrotropic activity of LATS.